Filter element for a filter device

ABSTRACT

The invention relates to a filter element for a filter device, having at least one filter housing ( 3; 4 ), wherein the filter element ( 1 ) comprises a receiving part ( 19 ) which, when the filter element ( 1 ) is located in the filter housing ( 3; 4 ) in the operational position, comes into fluid communication with a housing part ( 17; 18 ) of the filter housing ( 3; 4 ), which forms a fluid connection ( 9 ). The invention is characterized in that the receiving part ( 19 ) of the filter element ( 1 ) has an inner, first guiding path ( 37 ) for sealing contact to the housing part ( 17 ) of the filter housing ( 3 ) according to a first mode of construction and an outer, second guiding path ( 51 ) for sealing contact to the housing part ( 18 ) of the filter housing ( 4 ) according to a second mode of construction.

The invention related to a filter element for a filter apparatus havingat least one filter housing, wherein the filter element has a receivingpart, which, when the filter element is located in the filter housing inthe operational position, comes into fluid communication with a housingpart of the filter housing, forming a fluid connection. In addition, theinvention relates to a filter apparatus for use with such filterelements.

Filter elements of this kind are known from prior art. Widespreadapplication can be found having different designs with respect toconstruction, size and/or pressure level in filter apparatuses for thefiltration of a wide variety of technical fluids such as hydraulicfluids, cooling lubricants, fuels, lubricating oils and the like. Sincethe malfunction or even breakdown of such filter apparatuses can damageor destroy downstream systems, which can have an economic impact, theoperational reliability of the relevant filter apparatuses is of greatimportance. Consistent efforts have therefore been made by the industryto refine the components relevant to the filtration process with respectto increased functional reliability. As a result, these efforts have ledto the development of improved, novel filter elements with performancethat is improved as compared to previously used filter elements. Howeverwhen utilizing these advantages, one is still faced with the problem ofthe compatibility of such improved, new filter elements with existingfilter apparatuses, which are designed for use with previouslyconventional filter elements. In other words, in order to use thecorresponding, newly developed filter elements, it is necessary toreplace the filter housing in conventional filter apparatuses. Given thewidespread use of the filter apparatuses being considered with a mode ofconstruction of the filter housing that is common for conventionalfilter elements, which must be replaced with a filter housing of amodified mode of construction, the operational advantages of theimproved, new filter elements are scarcely of economic benefit.

In view of these problems, the object of the invention is to provide afilter element that is versatile and therefore of economic benefit.

According to the invention, this object is achieved by a filter elementhaving the features of claims 1 in its entirety.

According to the characterizing portion of claim 1, an essential featureof the invention is that the receiving part of the filter element has aninner, first guiding track for sealing contact with the housing part ofthe filter housing according to a first mode of construction, as well asan outer, second guiding track for sealing contact with the housing partof the filter housing according to a second mode of construction. Theoperational advantages that arise from the use of a correspondinglydeveloped, improved filter element can be utilized not only inconjunction with filter housings at a new stage in development, but alsowith existing filter apparatuses having a filter housing, the mode ofconstruction of which is adapted to previously conventional filterelements. The advantages of refined filter elements therefore do notneed to be obtained through the replacement of existing filterapparatuses.

Since the filter elements according to the invention can be operatedwith filter housings of a second mode of construction, improvingrefinements can also be utilized with the filter housing, so that it ispossible to realize substantial improvements in overall systemscomprising a filter element and filter housing.

In especially advantageous exemplary embodiments, both guiding tracks ofthe filter element are provided in a part of an end cap, which forms thereceiving part, said guiding tracks forming a mounting for an associatedfilter medium enclosing an inner filter cavity. The fixing of the filterelement by means of an end cap makes it possible to properly secure theposition of the filter element in the operational position in a simplemanner.

Especially advantageously, the arrangement can be such that thereceiving part has a pipe socket, which encloses an access opening tothe inner filter cavity at the end cap, forms the inner, first guidingtrack on the inner surface thereof, and forms the outer, second guidingtrack on the outer surface thereof. Here, the pipe socket not only formsboth guiding tracks for interaction with the corresponding housing partsof the filter housings of a different mode of construction, but alsoforms a reliable fluid communication between the inner filter cavity andthe fluid connection of the respective housing.

In especially advantageous exemplary embodiments, the inner, firstguiding track may be formed by an inner cylindrical surface of the pipesocket, which is provided on the housing part of the filter housing ofthe first mode of construction for contact with an outer cylindricalsurface of a socket.

In order to achieve an especially high degree of operationalreliability, the arrangement can be such that an external thread isformed on the outer, second guiding track, and an internal thread, whichis provided for interaction with the external thread, is formed on acontact surface on the inner surface of a socket of the housing part ofthe filter housing of the second mode of construction. Because thefilter element in is screwed into the operational position in thehousing in this manner, it is possible to ensure the stability of theposition of the filter element is ensured.

In order to seal the guiding tracks at the respective socket of thefilter housings of the first mode of construction or of the second modeof construction, the arrangement can be advantageously such that thepipe socket on the inner, first guiding track has a first sealingelement, which is disposed at the end part of this guiding track at aspacing from the end cap, and has a second sealing element on the outer,second guiding track, which is disposed at the initial part of thesecond guiding track adjacent to at the end cap.

The object of the invention is also a filter apparatus, which isprovided for use with filter elements according to the invention andwhich has the features of claim 7 in its entirety.

In the case of the first mode of construction of the filter housing,these may be conventional filter apparatuses currently in use, while thesecond mode of construction of the filter housing only allows the use offilter elements according to the invention, in which, in addition to aninner, first guiding track, provided to interact with the fluidconnection of conventional filter housings, an outer, second guidingtrack is provided for the refined second housing design.

Further embodiments of the filter apparatus are stipulated in thefollowing claims 8 to 11.

The invention is explained in greater detail below with reference to thedrawings. Shown are:

FIG. 1 a simplified, schematic longitudinal section of an exemplaryembodiment of the filter apparatus according to the invention, providedwith a filter element according to the invention, wherein the filterhousing corresponds to a first mode of construction;

FIG. 2 an enlarged section of the region in FIG. 1 designated as II;

FIG. 3 a longitudinal section similar to that in FIG. 1, however whereinthe filter element is accommodated in a filter housing of a second modeof construction, and

FIG. 4 an enlarged section of the region in FIG. 3 designated as IV.

FIGS. 1 and 2 show an exemplary embodiment of the invention, wherein afilter element 1 according to the invention is accommodated in a filterhousing designated as a whole as 3, which corresponds to a conventionalmode of construction as is widely used in the art. The filter housing 3has a main housing body 5, which by and large defines a hollow,cylindrically-shaped inner space for receiving the filter element 1. Atthe bottom 7, the housing 3 is closed with the exception of a centraloutflow opening 9, out of which, fluid cleaned during operation can bedischarged. The upper, open end of the main housing body 5 is closed bymeans of a removable housing cover 11 in the usual manner for suchapparatuses. This housing cover has an axial extension 13, which forms apartial cover for an inflow opening 15, so that the extension 13 forms adeflector plate in order to protect the filter element 1 from the flowof non-filtered fluids.

The housing part, which surrounds the outflow opening 9 in the bottom 7,which forms the fluid connection for releasing the filtrate, has theform of a socket 17 projecting in the direction of the filter element 1,i.e. projecting upward, which, in conjunction with a receiving part ofthe filter element 1, which has the form of a pipe socket 19, serves asa seat for an element, to which the filter element 1 is affixed in anoperational position forming a seal. FIGS. 1 and 2 show the filterelement 1 in this operational position, in which the filter element 1 issecured by the closed housing cover 11. As is usual in filter elements 1of this kind, this filter element has a filter medium 21, whichencompasses a fluid-permeable supporting tube 23 in the form of a hollowcylinder. During the filtration process, wherein non-filtered fluidsenter by means of the inflow opening 15 and flows through the filtermedium 21 from the outside inward, inner filter cavity 25 enclosed bythe supporting tube 23 forms the clean side. A valve insert 27 belongingto the housing cover 11, which, in combination with an end cap 29, sealsthe inner filter cavity 25 at the upper end, forms a pressure-operatedbypass device in a known manner, in order to form a bypass by means ofwhich the non-filtered fluids can reach the inner filter cavity 25 fromthe inflow opening 15.

As FIG. 2 more clearly shows, the pipe socket 19 serving as a receivingpart of the filter element 1 is integrally formed on the lower end cap31 of the filter element 1, said end cap forming an outer mounting 33for the end region of the filter medium 21. In addition to thesupporting tube 23 abutting the inner surface of the filter medium 21, ashort inner tube 35 projecting axially into the filter cavity 25 islocated at the end cap 31, the inner surface of which is aligned withthe inner surface of the socket 17 when the filter element 1 is in theoperational position.

In order for the pipe socket 19 forming the receiving part to interactwith the housing 1 in the first mode of construction shown in FIGS. 1and 2, the pipe socket 19 forms an inner, first guiding track 37 in theform of a smooth cylindrical surface on the inner surface thereof (seeFIG. 2), which is only interrupted by an annular groove 39 in thevicinity of the free, lower end for a sealing element 41 only shown inFIG. 1. In the case of the operational position, the inner, firstguiding track 37, in conjunction with the sealing element 41, thus formsa sealed contact with the outer cylindrical surface 43 of the socket 17(see FIG. 2). As this Figure clearly shows, the cylindrical surface 43of the socket 17 has a step 45 at the end thereof, which is abutted bythe end of the pipe socket 19 when in the operational position.

FIGS. 3 and 4 show that the filter element 1 according to the inventioncan also be operated in conjunction with a filter housing 4 of a secondmode of construction. This differs from the first mode of constructionin that the socket 18 interacting with the receiving part, i.e. with thepipe socket 19, of the filter element 1 is modified in such a way thatthat socket ensures improved stability of the position of the filterelement 1 by means of the formation of a threaded connection. For thispurpose, in addition to the inner guiding track 37, the pipe socket 19has an outer, second guiding track 51, which is provided for the sealingcontact on the inner cylindrical surface 53 of the socket 18 of thefilter housing 4 of the second mode of construction, wherein an annulargroove 55 is provided on the pipe socket 19 of the element seat 31 for asealing element 57 (see FIG. 3). This annular groove 55 is located atthe initial part of the pipe socket 19 adjacent to the end cap 31.Following this annular groove 55, the pipe socket 19 is provided with anexternal thread 59, which can be screwed together with an internalthread 61 on the inner surface of the socket 18 (see FIG. 4).

In the case of the operational position shown in FIGS. 3 and 4, the end63 of the socket 18 abuts the end cap 31. The free end of the pipesocket 19 rests on the bottom 65 of an annular space, which is definedbetween an inner ring 67 of the socket 18 and the inner cylindricalsurface 53 of the socket 18, and into which the pipe socket 19 extendswhen in the operational position. The sealing ring 41 held in theannular groove 39 of the pipe socket 19 thereby forms an additional sealvis-à-vis the socket 18 of the filter housing 4 according to a secondmode of construction.

1. A filter element for a filter apparatus having at least one filterhousing (3; 4), wherein the filter element (1) has a receiving part(19), which, when the filter element (1) is located in the filterhousing (3; 4) in the operational position, comes into fluidcommunication with a housing part (17; 18) of the filter housing (3; 4),forming a fluid connection (9), characterized in that the receiving part(19) of the filter element (1) has an inner, first guiding track (37)for sealing contact with the housing part (17) of the filter housing (3)according to a first mode of construction as well as an outer, secondguiding track (51) for sealing contact with the housing part (18) of thefilter housing (4) according to a second mode of construction.
 2. Thefilter element according to claim 1, characterized in that both guidingtracks (37, 51) are provided in a part (19) of an end cap (31) of thefilter element (1), which forms the receiving part, said guiding tracksforming a mounting (33) for an associated filter medium (21) enclosingan inner filter cavity (25).
 3. The filter element according to claim 1,characterized in that the receiving part has a pipe socket (19), whichencloses an access opening to the inner filter cavity (25) at the endcap (31), on which the inner, first guiding track (37) is formed on theinner surface thereof, and the outer, second guiding track (51) isformed on the outer surface thereof.
 4. The filter element according toclaim 1, characterized in that the inner, first guiding track (37) isformed by an inner cylindrical surface of the pipe socket (19), which isprovided on the housing part of the filter housing (3) of the first modeof construction for contact with an outer cylindrical surface (43) of asocket (17).
 5. The filter element according to claim 1, characterizedin that an external thread (59) is formed on the outer, second guidingtrack (51), and an internal thread (61), which is provided forinteraction with the external thread (59), is formed on a contactsurface on the inner surface of a socket (18) of the housing part of thefilter housing (4) of the second mode of construction.
 6. The filterelement according to claim 1, characterized in that the pipe socket (19)on the inner, first guiding track (37) has a first sealing element (41),which is disposed at the end part of this guiding track (37) at aspacing from the end cap (31), and has a second sealing element (57) onthe outer, second guiding track (51), which is disposed at the initialpart of the second guiding track (51) adjacent to at the end cap (31).7. A filter apparatus for use with filter elements (1) in accordancewith claim 1, having at least one filter housing (3; 4) for receiving atleast one filter element (1), having a receiving part (19), which, whenin an operational position in the housing (3; 4), comes into fluidcommunication with a housing part (17; 18) of the filter housing (3; 4),forming a fluid connection (9), characterized in that the filter housing(3; 4) in a first mode of construction (3) and in a second mode ofconstruction (4) each have a socket (17; 18) on the housing part, whichhas the fluid connection (9), wherein the socket encloses the fluidconnection (9), which, in the case of the first housing structure (3),has an outer cylindrical surface (43) for the sealing contact with aninner, first guiding track (37) of the receiving part (19) of the filterelement (1), and in the case of the second housing structure (4), has aninner cylindrical surface (53) for the sealing contact with the outer,second guiding track (51) of the receiving part (19) of the filterelement (1).
 8. The filter apparatus according to claim 7, characterizedin that an internal thread (61) is provided on the socket (18) of thefilter housing (4) of the second mode of construction, which is providedfor interaction with an external thread (59) on the outer, secondguiding track (51) of the receiving part (19) of the filter element (1).9. The filter apparatus according to claim 7, characterized in that thesocket (18) of the housing (4) of the second mode of construction has aninner ring (67), which delimits an annular space on the inner surface ofthe socket (18), in which space the receiving part (19) of the filterelement (1) engages when in the operational position in such a way thata sealing element (41) disposed on the inner, first guiding track (37)abuts the inner surface of the annular space.
 10. The filter apparatusaccording to claim 1, characterized in that the socket (17) of thehousing (3) of the first mode of construction has a step (45) on theouter cylindrical surface (43), which forms the contact surface for thefirst guiding track (37) of the filter element, said step abutting theend of the receiving part (19) of the filter element (1) located in anoperational position.
 11. The filter apparatus according to claim 1,characterized in that the end of the socket (19) of the filter housing(4) of the second mode of construction abuts the end cap (31) of thefilter element (1) located in an operational position.